Routine versus clinically driven laboratory monitoring of HIV antiretroviral therapy in Africa (DART): a randomised non-inferiority trial

BACKGROUND

HIV antiretroviral therapy (ART) is often managed without routine laboratory monitoring in Africa; however, the effect of this approach is unknown. This trial investigated whether routine toxicity and efficacy monitoring of HIV-infected patients receiving ART had an important long-term effect on clinical outcomes in Africa.

METHODS

In this open, non-inferiority trial in three centres in Uganda and one in Zimbabwe, 3321 symptomatic, ART-naive, HIV-infected adults with CD4 counts less than 200 cells per microL starting ART were randomly assigned to laboratory and clinical monitoring (LCM; n=1659) or clinically driven monitoring (CDM; n=1662) by a computer-generated list. Haematology, biochemistry, and CD4-cell counts were done every 12 weeks. In the LCM group, results were available to clinicians; in the CDM group, results (apart from CD4-cell count) could be requested if clinically indicated and grade 4 toxicities were available. Participants switched to second-line ART after new or recurrent WHO stage 4 events in both groups, or CD4 count less than 100 cells per microL (LCM only). Co-primary endpoints were new WHO stage 4 HIV events or death, and serious adverse events. Non-inferiority was defined as the upper 95% confidence limit for the hazard ratio (HR) for new WHO stage 4 events or death being no greater than 1.18. Analyses were by intention to treat. This study is registered, number ISRCTN13968779.

FINDINGS

Two participants assigned to CDM and three to LCM were excluded from analyses. 5-year survival was 87% (95% CI 85-88) in the CDM group and 90% (88-91) in the LCM group, and 122 (7%) and 112 (7%) participants, respectively, were lost to follow-up over median 4.9 years' follow-up. 459 (28%) participants receiving CDM versus 356 (21%) LCM had a new WHO stage 4 event or died (6.94 [95% CI 6.33-7.60] vs 5.24 [4.72-5.81] per 100 person-years; absolute difference 1.70 per 100 person-years [0.87-2.54]; HR 1.31 [1.14-1.51]; p=0.0001). Differences in disease progression occurred from the third year on ART, whereas higher rates of switch to second-line treatment occurred in LCM from the second year. 283 (17%) participants receiving CDM versus 260 (16%) LCM had a new serious adverse event (HR 1.12 [0.94-1.32]; p=0.19), with anaemia the most common (76 vs 61 cases).

INTERPRETATION

ART can be delivered safely without routine laboratory monitoring for toxic effects, but differences in disease progression suggest a role for monitoring of CD4-cell count from the second year of ART to guide the switch to second-line treatment.

FUNDING

UK Medical Research Council, the UK Department for International Development, the Rockefeller Foundation, GlaxoSmithKline, Gilead Sciences, Boehringer-Ingelheim, and Abbott Laboratories.

Clonal turnover of MACE-carrying peach-potato aphids (Myzus persicae (Sulzer), Homoptera: Aphididae) colonizing Scotland

Peach-potato aphids, Myzus persicae (Sulzer), collected in Scotland in the years 1995 and 2002-2004 were characterized using four microsatellite loci and three insecticide resistance mechanisms. From 868 samples, 14 multilocus genotypes were defined (designated clones A-N). Five of these (denoted A, B, H, M and N) carried modified acetylcholinesterase (MACE) resistance, the most recent resistance mechanism to have evolved in M. persicae. The current paper shows that the continued presence of MACE aphids is due to turnover, as clones A and B were replaced in field samples by clones H, M and N in later seasons. Thus, insecticide-resistant populations in Scotland can be attributed to multiple waves of rapid clone colonisations and not to the continued presence of stable resistant clones or mutation or sexual recombination in local populations. The MACE clones carried varying levels of the other insecticide resistance mechanisms, kdr and esterase. The presence of these mechanisms could alter the clones success in the field depending on insecticide spraying (positive selection) and resistance fitness costs (negative selection).

Simultaneous isolation of human BM hematopoietic, endothelial and mesenchymal progenitor cells by flow sorting based on aldehyde dehydrogenase activity: implications for cell therapy

BACKGROUND

ALDH(br) cells express high aldehyde dehydrogenase (ALDH) activity and have progenitor cell activity in several contexts. We characterized human BM ALDH(br) cells to determine whether cell sorting based on ALDH activity isolates potentially useful populations for cell therapy.

METHOD

We measured the expression of ALDH and cell-surface Ag by flow cytometry and compared the ability of sorted ALDH(br), and BM populations remaining after ALDH(br) cells were removed (ALDH(dim) populations), to develop into several cell lineages in culture.

RESULTS

The ALDH(br) population comprised 1.2+/-0.8% (mean+/-SD, n=30) nucleated cells and was enriched in cells expressing CD34, CD117, CD105, CD127, CD133 and CD166, and in primitive CD34(+) CD38(-) and CD34(+) CD133(+) progenitors. Most of the CD34(+) and CD133(+) cells were ALDH(dim). ALDH(br) populations had 144-fold more hematopoietic colony-forming activity than ALDH(dim) cells and included all megakaryocyte progenitors. ALDH(br) populations readily established endothelial cell monolayers in cultures. Cells generating endothelial colonies in 7 days were 435-fold more frequent in ALDH(br) than ALDH(dim) populations. CFU-F were 9.5-fold more frequent in ALDH(br) than ALDH(dim) cells, and ALDH(br) cells gave rise to multipotential mesenchymal cell cultures that could be driven to develop into adipocytes, osteoblasts and chondrocytes.

DISCUSSION

Hematopoietic, endothelial and mesenchymal progenitor cells can be isolated simultaneously from human BM by cell sorting based on ALDH activity. BM ALDH(br) populations may be useful in several cell therapy applications.

Bacillus sporothermodurans and other highly heat-resistant spore formers in milk

A recent example of a micro-organism causing undesired growth in consumer milk is Bacillus sporothermodurans producing highly heat-resistant spores (HRS) which may survive ultra-high temperature (UHT) treatment or industrial sterilization. Molecular typing showed a heterogeneous group of farm isolates (non-HRS strains), but a clonal group of UHT isolates from diverse European countries and other continents (HRS-clone) suggesting a common source. During a survey of Belgian dairy farms for the presence of potentially highly heat-resistant spore formers, high numbers of these spores were detected in filter cloth, green crop and fodder samples. The strain collection showed a high taxonomic diversity with 18 potentially new species and with Bacillus licheniformis and Geobacillus pallidus as predominating species overall. Seventeen B. sporothermodurans isolates were identified, mainly originating from feed concentrate. Heat resistance studies showed the UHT resistance of B. sporothermodurans spores present in industrially contaminated UHT milk, but a lower heat resistance of laboratory-grown strains (HRS and non-HRS). Hydrogen peroxide, used as sanitizer in the dairy industry, was found to induce higher heat resistance of laboratory-grown B. sporothermodurans strains to a certain level. This indicates that sublethal stress conditions may affect the heat resistance. By transmission electron microscopy, structural differences at the spore level were found between HRS and non-HRS strains. The data indicate that the attainment of extreme heat resistance is rather multifactorial.

Observations on the measurement of total antimony and antimony species in algae, plant and animal tissues

This paper describes our experiences with undertaking measurements of total antimony and antimony speciation in algae, plant and animal tissues. Digestion with nitric acid alone is suitable to release antimony from animal tissues. When organisms have high silica contents, e.g. some plants and algae, the addition of tetrafluorboric acid is required to dissolve silica as some antimony is retained by silica in extracts. Antimony in digested extracts is present as Sb5+ and hydride generation procedures can be used to determine total antimony concentrations, as total antimony in extracts will not be under estimated. Relatively non-aggressive solvents such as water, dilute nitric acid, sodium hydroxide and enzymes remove highly variable amounts of antimony (2-84%) from algae, plant and animal tissues. Addition of Sb3+ and Sb5+ to NIST CRM 1572 Citrus Leaves, pre- and post-extraction with water showed that Sb3+ is oxidised to Sb5+ while Sb5+ is redistributed amongst binding sites giving rise to artefacts. DOLT-2 and algae extracts indicated the presence of only inorganic antimony. A moss sample had inorganic antimony and a number of unknown antimony species in extracts. Future studies should explore the nature of the binding of antimony in tissues as solvents commonly used to extract metals and metalloids from algae, plant and animal tissues are not appropriate.

Crystallization and preliminary X-ray analysis of the ytxM gene product from Bacillus subtilis

The ytxM gene product from Bacillus subtilis has been cloned, expressed in Escherichia coli, purified and crystallized by the hanging-drop vapour-diffusion method using PEG 3350 as the precipitant. Multiple-wavelength anomalous dispersive X-ray data have been collected to 2.0 A resolution on a single selenomethionine-incorporated crystal. This crystal belongs to the primitive orthorhombic system, with approximate unit-cell parameters a = 44.3, b = 90.9, c = 136.1 A, alpha = beta = gamma = 90 degrees and two monomers in the asymmetric unit.

Exchange bias in spin-engineered double superlattices

Exchange bias has been observed in sputtered magnetic double superlattices which consist of a ferromagnetically coupled superlattice grown on an antiferromagnetically (AF) coupled superlattice. This system exhibits a parallel domain wall, a spin flop transition, and exchange bias when the anisotropy is large in the AF block. This work shows that neither the domain wall nor the spin flop are directly related to exchange bias but that the anisotropy is essential.

A role for secondary V(D)J recombination in oncogenic chromosomal translocations?

Chromosomal translocations are hallmarks of certain lymphoproliferative disorders. Indeed, in many leukemias and lymphomas, translocations are the transforming event that brings about malignancy. Recurrence of the immunoglobulin (Ig) and T-cell receptor (Tcr) loci at the breakpoints of oncogenic chromosomal translocations has led to speculation that the lymphocyte-specific process of V(D)J rearrangement, which is necessary for the generation of functional Ig and TCR antigen receptors on B and T lymphocytes, mediates translocation. Recent studies have led to a fuller understanding of the molecular mechanisms of V(D)J rearrangement and have revealed that the V(D)J recombinase possesses latent transposase activity. These studies have led to plausible models of illegitimate V(D)J recombination producing chromosomal translocations consistent with those present in lymphomas and leukemias. Errors of V(D)J recombination may even generate lymphomas with the phenotypes of mature cells. For example, follicular and Burkitt's lymphomas have been classified by phenotype and somatic genotype as malignant germinal center (GC) B or post-GC B cells. The GC is a site of affinity maturation where B cells undergo V(D)J hypermutation and Ig class switch; in addition, much evidence has accumulated to suggest that GC B cells may also support secondary V(D)J recombination. Interestingly, all three of these elements, genomic plasticity, mutation, and translocation breakpoints near switch sites or recombinational elements, are characteristic of certain lymphomas. The high frequency of lymphomas carrying these GC markers suggests that the GC reaction may play a significant role in lymphomagenesis.

Yield comparisons and cropping patterns of Kensington Pride mango selections

Thirty-three trees were identified from commercial orchards in Queensland during the 1990–91 and 1991–92 seasons to investigate the potential of improving the agronomic and fruit quality aspects of Kensington Pride mango. These selections were grafted and planted in a replicated field trial in the Burdekin district for comparative evaluation. Cropping characteristics were recorded annually until the trees reached 10 years of age. Small yield variations were observed between the selections, with no significant differences between the top 19�selections. No single selection had outstanding yields, however 2 selections had significantly lower yields than the rest. These findings indicate the difficulty in significantly improving Kensington Pride mangoes through selection from existing commercial germplasm. Sixteen of the best performing selections from the field trial were used as a top group to investigate the cropping characteristics of the cultivar. The average annual increase in yield and fluctuations from this average were modelled. The first significant crop was 15.7 kg per tree in year 4 and modelled yields increased by 23.3 kg per tree per year thereafter to year 10. There were significant annual fluctuations from the modelled trend with yields varying from between –44.7 to +35.7% of the expected yield. As fruit number per tree increased, average fruit weight decreased by 0.14g for every extra fruit.

Drugs for neglected diseases: a failure of the market and a public health failure?

Infectious diseases cause the suffering of hundreds of millions of people, especially in tropical and subtropical areas. Effective, affordable and easy-to-use medicines to fight these diseases are nearly absent. Although science and technology are sufficiently advanced to provide the necessary medicines, very few new drugs are being developed. However, drug discovery is not the major bottleneck. Today's R&D-based pharmaceutical industry is reluctant to invest in the development of drugs to treat the major diseases of the poor, because return on investment cannot be guaranteed. With national and international politics supporting a free market-based world order, financial opportunities rather than global health needs guide the direction of new drug development. Can we accept that the dearth of effective drugs for diseases that mainly affect the poor is simply the sad but inevitable consequence of a global market economy? Or is it a massive public health failure, and a failure to direct economic development for the benefit of society? An urgent reorientation of priorities in drug development and health policy is needed. The pharmaceutical industry must contribute to this effort, but national and international policies need to direct the global economy to address the true health needs of society. This requires political will, a strong commitment to prioritize health considerations over economic interests, and the enforcement of regulations and other mechanisms to stimulate essential drug development. New and creative strategies involving both the public and the private sector are needed to ensure that affordable medicines for today's neglected diseases are developed. Priority action areas include advocating an essential medicines R&D agenda, capacity-building in and technology transfer to developing countries, elaborating an adapted legal and regulatory framework, prioritizing funding for essential drug development and securing availability, accessibility, distribution and rational use of these drugs.

Cloning, purification, crystallization and preliminary crystallographic analysis of Bacillus subtilis LuxS

LuxS of Bacillus subtilis is a member of a novel family of proteins with a potential role in quorum sensing, controlling important aspects of cellular physiology in a range of microbial species. B. subtilis luxS was cloned, expressed in Escherichia coli, purified and crystallized using the hanging-drop method of vapour diffusion with ammonium sulfate as the precipitant. The crystals belong to one of the enantiomorphic space groups P6(1)22 or P6(5)22, with approximate unit-cell parameters a = b = 63.6, c = 151.5 A and one subunit in the asymmetric unit, corresponding to a packing density of 2.5 A(3) Da(-1). The crystals diffract X-rays to at least 1.55 A resolution on a synchrotron-radiation source. Determination of the structure will provide insights into the key determinants of function of this class of proteins, for which no structures are currently available.

The quality of care by private practitioners for sexually transmitted diseases in Uganda

One of the limited number of strategies available to reduce the spread of human immunodeficiency virus (HIV) infections in sub-Saharan Africa is the effective treatment of other, curable, sexually transmitted diseases (STDs). At present, a large proportion of people with STDs either treat themselves at home or seek treatment from private sector practitioners (PSPs) rather than use publicly funded services. A randomized controlled trial of the efficacy of a behavioural intervention with or without improved STD services is being carried out in Masaka, a rural area of south-western Uganda. The trial involves three groups, each covering six parishes. People living in one group of parishes receive information, education and communication activities (IEC) to increase public awareness regarding STDs and HIV/AIDS. The second group receives the same IEC interventions with improved treatment of STDs by both public and private service providers. The third group receives community development activities unrelated to HIV. In order to improve our understanding of how the quality of care provided by PSPs might be ameliorated, we interviewed 36 PSPs in the trial area, and made an assessment of the care they were providing. We also carried out six focus group discussions with patients to obtain their opinions on private services. PSPs in the intervention arm of the trial, who had attended meetings dealing with the syndromic management of STDs, referred to syndromes 82% of the time compared with 12% in the control arms, a mean difference of 70% (p < 0.001); stocked locally appropriate antibiotics 76% of the time compared with 52%, a mean difference of 24% (p < 0.001); and are more likely to prescribe appropriate drugs 82% of the time compared with 27%, a mean difference of 55% (p < 0.001). This small study suggests that PSPs can help improve the management of STDs.